But, and this is super important, you cannot ever tell anyone that you've been recording her. Only tell us, here. Or, better yet, don't even tell us. Just listen to us, pay attention, and take appropriate action, discreetly. Tell no one else in real life, except your own attorney in the privacy of an attorney-client consultation. If you have any interactions with law enforcement, be sure to record those as well and get the officers name, date and time in there somehow. Then, share later, in private, with your attorney.
A lot of guys want to play "ah hah! I've got you now!" games with their recordings. They feel a sense of "power" from having such evidence and want to slap the < female dog > in the face with it. Don't do it. Take the fact that you're recording to the grave with you. Seriously. Especially if you're not in a "one-party" state, when it comes to recordings.
For every guy that ends up needing his recording in court, there are dozens and dozens who do not. However, if you need it, you NEED IT big time. There are very few situations in which they will be beneficial to you. The judge in your divorce does not care about your arguments or other "normal" marital discord and drama associated with divorce. S/he (hizzoner) has seen and heard it all.
Now, if you have a recording of her making devil voices, threatening to burn you in your sleep, harm kiddos, harm herself, etc. then the judge will care about that kind of thing. Other than that, it's all pretty much "meh" to the judge. It may be a HUGE deal in your own emotional life, but it's just another day in divorce court for all of those who work in the courts. Try to keep a healthy perspective on it.
When all was said and done with my divorce, I was left with GBs of recordings on a hidden storage location. They'll never see the light of day. I have no desire to listen to them, and, as they years have gone by, am leaning more and more toward deleting them. It actually feels strange to still have them, but the peace of mind that came from having them during the divorce process was priceless.